Percussion fuses for unrotated projectiles



H. JUNGHANS ETAL PERCUSSION FUSES FOR UNROTATED PROJECTILES June 27, 1961 I5 Sheets-Sheet 1 Filed April 1, 1958 Fig. I

June 27, 1961 H. JUNGHANS ET'AL 2,989,924

PERCUSSION FUSES FOR UNROTATED PROJECTILES Filed April 1, 1958 3 Sheets-Sheet 2 Fig. 2 Fig. 3

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1 I i I INVENTORS June 27, 1961 H. JUNGHAN-S ETAL 2,939,924

PERCUSSION FUSES FOR UNROTATED PROJECTILES Filed April 1, 1958 3 Sheets-Sheet 3 INVBVTORJ H -Ju7zgLzrz BY P, Kane,

A ttw- 2,989,924 PERCUSSION FUSES FOR UNROTATED PROJECTILES V Helmut Junghans, Schramberg-Sulgeri, Eckenhof (Schwarzwald), Wurttemberg, Germany, and Paul Kaiser, Weihergasse 28, Schrambe'rg (Schwarzwald), Wurttemberg, Germany Filed Apr. 1, 1958, Ser. No. 725,606 I Claims priority, application Germany Apr. 3, 1957 4 Claims. (Cl. 102-48) The invention relates to direct percussion fuzes for unrotated projectiles and a safety device driven by the reaction pressure. The safety device is to act both as a safety device during transport and also as a time fuze in the barrel or firing frame and for a certain previous time interval. The fuze is characterised by a delay mechanism having at least one axially displaceable driving weight and at least one axially displaceable counterweight which is made lighter, depending on the predetermined delay time, both weights being made as toothed racks and being coupled by a pinion, and a striker pin safety device which is controlled by one of the two weights. Such an arrangement offers adequate safety against impacts during transport, which are of comparatively short duration by contrast to the forces of acceleration which are elfective on firing an unrotated projectile, so that the parts serving as the safety device are only removed by a small amount from their rest position and are still not able to liberate the safety device which they control. By means of the co-operation betweenthe driving weight and the counter-weight, it is possible in a simple manner to obtain the delay times which are valuable as regards safety in the barrel and in flight. It can be advantageous, for the purpose of further delaying the operation of the delay mechanism, to cause the pinion to drive a supplementary escapement, preferably one which consists of an escapement wheel and a pallet. The counter-weight can have associated therewith a return spring for the purpose of returning it to its initial position when the acceleration has ended and in this way initiating the arming of the impact device. Further features and advantages of the invention will be apparent from the following description of one constructional example, from the drawing and the claims.

FIG. 1 is a side view of the fuze as a longitudinal section on the line I-I of FIG. 6; the parts of the fuze are in their initial positions prior to firing;

FIG. 2 shows the parts of the fuze during the acceleration;

FIG. 3 shows the parts of the fuze when the acceleration has ended;

FIG. 4 is a side view of the escapement with the fuze cap broken away;

FIG. 5 is a section on the line V-V of FIG. 1, and

FIG. 6 is a section on the line VIVI of FIG. 1.

In the drawings, 10 represents the fuze body, 11 the fuze cap, 12 the primer, 14 the primer screw, and 15 the impact plunger.

Arranged in the fuze body are two axially parallel bores 10a and 10b which are closed at the upper end by discs 16 and 17. Guided coaxially through these bores are rods 18 and 19 which slide in corresponding bores in the cover discs 16 and 17 and in the common base for the bores 10a and 10b (at 10a and 10b). The rods 18 and 19 are interconnected by transverse members 20 and 21; the striker pin 22 is rivetted into the cross-member 2t) and the igniter pin 23 in the cross-member 21.

In order to retain the impact-transmitting linkage 18, 19, 20, 21, 22 and 23 in its safe position (FIGS. 1 and 2), a double-armed lever 24 is mounted to swivel on the bearing screw 25 (FIGS. 1, 2, 3 and 6). Fixed to one arm of the lever 24 is the spacer 26, which supports the Patented June 27, 1961 2 cross-member 20 in the safe position (FIG. 6), while the other arm carries the feeler pin 27 which projects downwardly into the bore 10b and co-operates with a movable part yet to be described. A pre-tensioned leaf spring 28 fixed at 28a to the fuze member 10 tends to To tate the double lever 24 into the armed position (counter clockwise in FIG. 6). It is clear that with the lever 24 in the armed position, if the fuze on the projectile meets any resistance, the cap 11 is compressed and the stn'kei pin 15 as well as the parts 22, 20, 19, 18, 21 and 23 are urged rearwardly and the primer 12 is perforated.

In order to prevent the safety lever 24, the spacer 26 and the feeler pin 27 from swinging outwardly before tiring, for example during transport, and also during the ace celeration phase and during a predetermined interval of time after such acceleration phase, a delay mechanism is provided which consists of the following parts: provided for sliding movement on the rod 18 in the bore 16a is the substantially cylindrical driving weight 29. It is formed with teeth 29a by which it meshes with a pinion 31 mounted in the fuze body at 10c (FIG. 5) and at 30. The teeth 29a end at 29a for reasons to be referred to later.

Arranged in the bore 1% so as to be slidable on the rod 19 is another weight, which is referred to as the counter-weight 32. It isprovided over its entire length at 32a with teeth by which it meshes with the pinion 31. The counter-weight 32 is also provided with a blind bore 32b which is open towards the front end of the fuze in order partially to accommodate the return spring 33 therein. Connected fast to the pinion 31 (FIG. 5) is the escapement wheel 34 which cooperates with the pallet 36 mounted to oscillate about the pin 35 on the fuze body 10.

As shown in FIGS. 1 to 3, the pinion 31 is arranged somewhat above the middle-length position of the two bores 10a and 10b which are of equal length and the paths available to the weights 29 and 32 have the following dimensions: 7

In the initial position (FIG. 1), the driving weight 29 is in its uppermost position near the front end of the fuze; its teeth 29a mesh with the pinion 31; its end face 2% abuts against the cover disc 16. The counter-weight 32 at this moment is just still in engagement with the pinion 31 by means of its teeth 320. Between the lend face 32c of the counter-weight and the base surface 10b" of the bore 1011, however, there is still some free space, this space being more than is necessary to allow the teeth 32a to come out of mesh with the pinion 31. It is more fully described hereinafter that the counter-weight 32, if it were to move still further downwardly from the position shown in FIG. 1, would shortly thereafter become disengaged from 31 and would cover the last part of its movement substantially suddenly and without any retardation under the action of the spring 33, for the purpose of freeing the feeler pin 27 bearing on its periphery for sudden movement.

summarising, the operation of the fuze is as follows: if the projectile falls in a particularly unfavourable manner, with the base of the projectile striking a hard surface, so that axial forces of acceleration become operative, the driving weight 29 can move backwardly a small distance and displace the counter-weight forwardly through the pinion 31 against the action of the spring 33. The delay mechanism is however so designed, especially because of suitable choice of the lengths of movement for the two weights, that the shock which becomes operative on falling on to a hard surface is essentially not sufficient, i.e. has subsided for a long time before the weights 29 and 32 have covered a substantial part of their operative path. In actual fact, after the shock has subsided, the

spring 33 will return the two weights to their initial position as shown in FIG. 1.

On firing the projectile from a barrel, a rocket firing frameor the like, the. acceleration is. operative for a predetermined time to which the effective paths of the weights 29 and 32 and the strength of the spring 33 are (adjusted, so that during the acceleration, the driving 'Weight 29 has reached the bottom a. of the bore 10a, and shortly before this position is reached, its teeth 29a have become disengaged from the pinion31 because of the shortening of the teeth at 29a. ward movement of the driving weight 29, it has displaced With the backthe counter-weight 32 forwardly, tensioningtherspring 33. The moment immediately after the driving weight 29 has come out of engagement with the pinion 3. and

with the counter-weight 32 in its foremost position with 'the'spring 33 tensioned is shown in FIG. 2. It will also be seen that a bolt 37 in the form of a biased leaf spring fixed. at 37a in the fuze body has taken up a position be fore the front end of the driving weight 29, this spring having previously been hearing on the peripheral surface of the Weight.

In the position which is shown in FIG. 2, the fuze is still safe, because the feeler pin 27 on the lever 24 is still bearing on the circumference of the weight 32 and because of the spacer 26 supports the cross-member .20

of the fuze linkage. It is in this way that. safety in the barrel is ensured.

7 After the driving weight 29 has become disengaged from the pinion 31, the counter-weight is merely subject to rearwardly driving forces, substantially the force of the spring 33, which as shown in FIGURE 3, displaces the counter-weight rcarwardly while impeded by the delay device 34, 36, this movement being beyond the safe position shown in FIG. 1 until it strikes on the base 10b" of the bore 101;. It will be seen from thedrawing that tance which the projectile has travelled after completing the acceleration, i.e. substantially after leaving the barrel or the like, until the armed position shown in .FIG. 3 is .reached, depends on the design of the delay mechanism.

It is also to be mentionedthat on impactof the proasseuse 4. jectile, the fuze cap 11 must be deformed in order to enable the striker pin 15 to become operative. The delay in the actuation of the impact device in combination with this deformation of the fuze cap is desirable and can begivena certain adjustment by choice of material and choice of the dimensions of the fuze cap, because with anti-aircraft ammunition, for example, the ignition is only to take place when the projectile has penetratedja certain distance into the target.

We claim:

1. A percussionfuze for non-rotary projectiles with direct impact anda safety device driven by back pressure, comprising' adelay mechanism having at least one axially displaceable driving weight and at least one axially displaceable counter-weight which is of lighter Weight than the driving weight each weight having a gear rack thereon, a pinion rotatably mounted in the projectile and coupled to mesh with the gear rack of each weight, an igniting pin safety device connected for control by one of the two weights, each weight being provided with a longitudinal bore, a rod provided for each bore to guide the weights thereon, a transverse member secured to each end of the pair of rods to connect the two rods to each other by the transverse members, a spacer for one of the transverse members at one end thereof, and an ignition pin secured to the other transverse member.

2. A percussion fuze according to claim 1, in which a double-armed lever is provided on which the spacer is secured and which is rotatable on an axis parallel to the axis of the ignition pin, and in which a spring is provided to urge the lever to its non-safety position.

3. A percussion fuze according to claim 1, in which a double-armed lever is provided on which the spacer is secured, and in which a feeler member is provided and mounted on the lever to contact the counter weight in the'safety position.

4. A percussion fuze according to claim 1, in which a spring bolt is provided to block and hold the driving weight at the end of its path of movement.

References Cited in the file of this patent UNITED STATES PATENTS 561,506 Felts June 2, 1896 1,943,706 Varaud Jan. 16, 1934 2,685,253 Apotheloz Aug. 3, 1954 2,836,118 Hjelm May 27, 1958 FOREIGN PATENTS 327,511 Italy July 13, 1935 

